Munich, which keeps grabbing global accolades as a progressive city, isn't resting on its laurels. It's up to some more good ideas, this time on the smart grid front.

Utility company SWM (Stadtwerke München, or Munich City Utilities) has teamed with Siemens AG to operate a dozen small power stations, including six renewables installations, as one "virtual power plant" from which SWM balances loads and sells excess generation to outside its grid area.

One of SWM's small Munich hydro plants.

"The main aim of SWM is to improve the reliability of planning and forecasting for decentralized power generation sources," the company says in a joint press release with Siemens.

The companies have integrated a total of 20 megawatts of capacity from the 12 plants which include 5 hydro stations, 1 wind farm, and 6 "unit-type cogenerating stations" (the release does not elaborate on the fuels).

Stephan Schwarz, SWM's director for utilities and technology, says that technology from Siemens helps the utility make use of spikes in renewable power generation (wind turbine production varies with the way the wind blows, for instance) that could otherwise go to waste or overload the grid.

"That is precisely what a smart grid is all about," says Schwarz.

SWM is using a Siemens "distributed energy management" system called DEMS, which makes note of weather forecasts, current electricity prices, and demand, and then plans production accordingly. A windy forecast, for instance, would cue more reliance on the wind farm.

Greetings from Munich.

"The calculated deployment schedule consequently minimizes the costs of generation and operation n the interconnected plants making up the virtual power station," the release states.

The system makes use of software in communications technologies that connect the 12 plants, including LAN, WAN, GPRS and ISDN. The technology comes largely from the Smart Grid division of Siemens' Infrastructure and Cities group.